Graphene NonNullConnection

nonnull_connection.py

class NonNullConnection(graphene.relay.Connection):
    class Meta:
        abstract = True

    @classmethod
    def __init_subclass_with_meta__(cls, node=None, **options):
        if node is not None and not isinstance(node, graphene.NonNull):
            node = graphene.NonNull(node)

        super(NonNullConnection, cls).__init_subclass_with_meta__(
            node=node, **options
        )

        edges_field: graphene.Field = cls._meta.fields['edges']
        field_type: graphene.NonNull = edges_field._type
        edges: graphene.List = field_type._of_type
        edge = edges._of_type

        cls._meta.fields['edges'] = graphene.Field(
            graphene.NonNull(
                graphene.List(
                    graphene.NonNull(edge)
                )
            )
        )